Problems with bad spark C (Ms1 ver 3.0)

jeff01 · Post by **jeff01** » Mon Aug 11, 2008 7:46

Sorry because of my bad english but I have a problem with my megasquirt and I hope to find help from here.

I have a BMW 335 (M30 engine) and 2 ford coilpacks and I use 1 coilpack as a half of it

I used a opel omega coilpack but spark B output burned down. I have owned this ecu about 6 months but there are always problems with spark C (I have changed already 2 times spark C vb921 transistor )

I made a litte video of testing coil input with indicator : http://www.youtube.com/watch?v=SHqgDo70CIM
First there was spark A connekted and then I switched it to spark C. Do you see any difference? Sometimes it goes hot and cuts the spark for few seconds at all. The problem is not in wires (It was same when I mesaured on vb921) Car makes a 13,9-14,2 on quarter mile but I feel that there is onla a 2/3 of spark c.

teg · Post by **teg** » Mon Aug 11, 2008 19:47

Have you connected coil supply behind fuel pump relay? If not, do it. This will prevent coil or vb921 to burn if spark c remains high.

jeff01 · Post by **jeff01** » Mon Aug 11, 2008 21:02

thanks for your answer but could you explain to me what it changes ? Is there really difference from where I take the +12v? Sometimes it runs for 3 sec. and doesn´t run for a second and many minutes so just jumps up and down, up and down....

teg · Post by **teg** » Tue Aug 12, 2008 8:22

It will just protect coil and driver-igbt when engine stalls. Maybe stalling engine will cause spark C to leave on? If spark C stays constantly on, it will burn vb921 or coil.

You should also update your firmware to latest version.

jeff01 · Post by **jeff01** » Tue Aug 12, 2008 20:15

I´m using latest firmware. I´ll try tomorrow taking +12 from fuel pump relay

teg · Post by **teg** » Tue Aug 12, 2008 20:33

Of course taking +12V doesn't help anymore if vb921 is already broken - it just protects in future over currents.

jeff01 · Post by **jeff01** » Thu Aug 14, 2008 17:21

VB921 isn´t broken (I tried to change it with spark A) but still same shit. If I measure with multimeter it shows me lower numbers and if I use a indicator it flashes few times less than other outputs...
Grounds to the FETs are taken from same place (engine) and it´s better than good

jeff01 · Post by **jeff01** » Fri Aug 29, 2008 7:52

My car works great now

(I switched off the fan output because my frend told me that I can´t use it with more than 2 fets.)